Well, pick up a Lightnin' Hopkins disc and decide for yourself. You owe it to yourself.
Lightnin' was very special. He had an exceptional voice for the blues, one of the very best, and a guitar style that went hand-in-glove with it. He is one of the handful of blues artists that everyone interested in the blues needs to come to grips with, one way or another.
Maybe pick up first some of the more raw electric stuff that he did in the mid-50s. It is the most urban of his output, and also some of the very best. The Herald recordings should do the trick. The Modern recordings would as well. Lightnin' was not rural, but he was very downhome in the sense of a Muddy Waters, Howlin' Wolf, or John Lee Hooker.
John L's got it right. If you pick up Jake Head Boogie (Ace) - Modern recordings, The Herald Recordings Vol. 1 & 2 (Collectables), and perhaps an Arhoolie - maybe Lightnin' or Texas Blues - for later Lightnin', you'll have the foundation of a good Lightnin' Hopkins collection.
The Gold Star Sessions 1 & 2 (Arhoolie) or The Complete Aladdin Sessions (EMI) could substitute for the Ace/Modern volume, but Jake Head Boogie would be my personal choice.
The Herald material was issued on a great single CD, Remember Me, on the Ember label. Its o/p, but since it was a UK label, it might turn up there in a used store, or somewhere on the net. I don't have the Collectables issues, but given that label's rep for occasional sketchiness, you might try and go for the Ember, if it turns up.
Lightnin' recorded a lot, especially in later years - it's not an overstatement to say that he was over recorded - so I find it best to be very choosy with his later recordings.